Height adjustment for changing table

ABSTRACT

The apparatus is a height adjustment assembly for a child&#39;s changing table with support tubes inserted into sockets at the top of a supporting structure such as a play yard. A height adjustment fixture external to the support tubes rests on top of the supporting structure and has a vertical series of recesses such as slots or holes and a ring through which the changing table&#39;s support tube slides. The changing table has an attached latching device that locks into the recesses to hold the table at several heights above the supporting structure. Alternate embodiments include a structure in which the height adjustment fixture contains the latching device and the recesses are in the changing table.

This application is based upon U.S. Provisional Patent Application Ser.No. 60/535,083 filed Jan. 8, 2004, and is a Divisional application ofSer. No. 11/021,206 filed Dec. 23, 2004.

BACKGROUND OF THE INVENTION

This invention deals generally with changing tables for infants, andmore specifically with a height adjustment apparatus for a changingtable installed on top of a structure such as a child's play yard.

Children's playpens, now more often called play yards, are a commonlyavailable accessory for use with infants and small children. It is notat all unusual for parents to take a folding play yard along on a tripor visit in order to provide a space for the child to play and sleep.There is also another accessory for children that is just as vital, butnot taken out of the child's home as frequently. That is a changingtable or bassinet.

However, there are now available some changing tables that simply attachto a play yard and therefore are not at all difficult to take out of thehome along with the play yard. Most of these tables take advantage ofthe height of the sides of the play yard and are attached to the top ofthe play yard sides.

U.S. Pat. No. 5,339,470 to Shamie discloses one such combination playpenand changing table that re-hangs the bottom of the playpen from shortstraps attached to the horizontal top rails of the playpen in order toprovide a somewhat higher surface for changing the child. U.S. Pat. No.5,553,336 to Mariol uses a different approach by providing a completeassembly that resembles a second layer of the play yard that fits intowells on the top four corners of the play yard. Another type of changingtable available is supported off one corner of a play yard, and it isrotated beyond the walls of the play yard when not in use.

The problem with all such arrangements is that they furnish only oneheight for the changing table, and that one height, which is keyed tothe existing height of the play yard walls, is usually too low for anadult to use with comfort, because adults of average height must benddown to the level of the changing table. Furthermore, any changing tablewith a single pre-designed height can not possibly suit all adults.

It would be very beneficial to have an uncomplicated changing table thatattaches to the top of a play yard and is easily adjustable toaccommodate adults of different heights.

SUMMARY OF THE INVENTION

The present invention provides a simple structure for attaching a heightadjustable changing table to the top of a play yard or other structure.To accept the support structure of the changing table, the play yard orother supporting structure requires only that a socket with an open topbe attached to an upper edge of the supporting structure. It is probablymost convenient and most stable if two sockets are mounted near twoupper corners of a play yard. A vertical support for the changing tablethen fits into each socket, and both the changing table and the entireheight adjustment assembly are attached to the changing table withoutany further modification to or addition of internal structures foreither the play yard support or the changing table support.

The changing table support is attached to the changing table structureby conventional means such as rivets or screws, and the heightadjustment assembly fits within the changing table structure, but theheight adjustment assembly is external to both the support on thechanging table and the socket on the play yard.

The main part of the height adjustment assembly of the preferredembodiment is a height adjustment fixture that contains three sections.One section is a coupling, which in the preferred embodiment is a ringthat is horizontally oriented as it fits around the changing tablevertical support just below the location where the changing tablesupport protrudes out of the changing table. An extension orientedparallel to the axis of the coupling ring is attached to and slightlyoffset from the coupling ring and contains the other two sections of thefixture. The second section is a cylindrical tube, the axis of which isparallel to the axis of the coupling ring and the axis of the changingtable support. This tube fits within the changing table, and into acylinder integrated into the changing table structure. The tube slideswithin the cylinder to maintain alignment between the changing table andthe third section which is a rack assembly.

The rack assembly is a linear strip attached to the outside of thecylindrical tube, with the linear strip containing a series of slots andseparating lands so that it resembles the rack of a gear and rackassembly. In one embodiment of the invention, a gear mounted on thechanging table engages the lands, and turning the gear raises or lowersthe changing table.

The preferred embodiment of the invention uses a spring loaded leverthat engages the slots, but permits the height of the changing table tobe manually lifted or lowered when the lever is pushed to move itslatching end out of the slots.

The particular benefits of the height adjustment assembly of theinvention are simple structure, inexpensive manufacturing, ease of use,and attachment to any supporting structure with nothing more than theaddition of one or two tubular sockets at the top of the supportingstructure. In particular, there is no requirement to put holes in any ofthe tubular structure of the supporting structure or install complexlocking mechanisms within the supports of either the changing table orthe supporting structure to which it is attached.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial sectional side view of the height adjustmentassembly of the preferred embodiment of the invention installed within achanging table that is shown atop a play yard.

FIG. 2 is a perspective view of the height adjustment fixture of thepreferred embodiment of the invention of FIG. 1.

FIG. 3 is a side view of an alternate embodiment of the heightadjustment assembly of the invention.

FIG. 4 is a perspective view of another alternate embodiment of a heightadjustment assembly of the invention.

FIG. 5 is a perspective view of the coupling and latch assembly of thealternate embodiment of FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a partial sectional side view of height adjustment assembly 10of the preferred embodiment of the invention installed within changingtable 12 shown atop play yard 14, and FIG. 2 is a perspective view ofheight adjustment fixture 11 of the preferred embodiment of theinvention. The view of height adjustment fixture 11 in FIG. 2 is fromthe opposite side of the view shown in FIG. 1 in order to better showthe structure of height adjustment fixture 11.

Height adjustment fixture 11 of FIGS. 1 and 2 includes a series of atleast two slots 16 alternating with lands 18 which, when installedwithin changing table 12, are aligned in a vertical orientation. Slots16 and lands 18 are formed on support structure 20, and tube 22 isattached to support structure 20 on surface 24 opposite lands 18. Heightadjustment fixture 11 also includes coupling ring 26 which is attachedto support structure 20 at the end of support structure 20 remote fromopening 21 of tube 22. Coupling ring 26 is attached to support structure20 at surface 28 which is the surface most remote from lands 18, so thataxis 27 of coupling ring 26 is parallel to axis 23 of tube 22 and toaxis 31 of changing table support 30, and coupling ring 26 has nointerfering structures on either side of it along its axis 27.

As shown in FIG. 1, the clearance on both sides of coupling ring 26permits height adjustment fixture 11 to be installed within changingtable 12 and perform its function although it need not be permanentlyattached to changing table 12. For changing table 12 to accommodateheight adjustment fixture 11, changing table 12 itself needs threestructures. One is changing table support 30 which can be a basic tubestructure that is used to attach most accessories to supportingstructures such as play yard 14. Changing table support 30 is attachedto changing table 12 by any conventional means such as hole 32 andfasteners 34.

The attachment of changing table 12 to play yard 14 is also conventionalin that holding fixture 36 with socket 38 is attached to play yard 14 atan upper location, such as adjacent to a corner where horizontal rail 40is attached to vertical support 42. Socket 38 in holding fixture 36 canthen accept any simple rod or tube, such as changing table support 30,as long as the tube is of smaller diameter than socket 38. However, suchsimple holders for accessory structures provide no height adjustmentsince the lower part of the accessory structure would merely sit uponholding fixture 36.

The simple structure of height adjustment fixture 11 furnishes a vitalpart of the height adjustment with no modification of either support 30or holding fixture 36. In the preferred embodiment shown in FIG. 1,height adjustment fixture 11 is shown installed in changing table 12.This is accomplished by slipping coupling ring 26 over changing tablesupport 30 so that the bottom surface 29 of coupling ring 26 rests uponholding fixture 36. Tube 22 of height adjustment fixture 11 then fitsinto a socket concentric with tube 22 within changing table 12 and aidsin aligning height adjustment fixture 11 with changing table 12. Tube 22also holds spring 44. Spring 44 is a compression spring, which is shownwith dashed lines in FIG. 1 and inserted within tube 22 in FIG. 2, hasits upper end against an inner surface of changing table 12, and servesto overcome any friction between tube 22 and its socket. Spring 44 thusassures that height adjustment fixture 11 continues to rest on holdingfixture 36 of play yard 14 as changing table 12 is raised.

In regard to stability and alignment, it is worthwhile to note that themost typical installation of height adjustment assembly 10 of thepresent invention is in pairs with one on each of two supports 30located at opposite ends of changing table 12. The two supports areinstalled into holding fixtures 36 located near adjacent corners of playyard 40. Such an arrangement provides an appropriate length for thechanging table and does not require any locking apparatus to preventsupports 30 from rotating within fixture 36.

Height adjustment assembly 10 requires one more device attached tochanging table 12. That is lever 46 which holds changing table 12 in oneof the height positions provided by slots 16. Lever 46 rotates aroundpivot point 48 when lever handle 50 is pushed toward lands 18, and aslever 46 rotates, latch 52 moves out of the slot 16 in which it islodged. This permits changing table 12 to be manually raised or lowered.When lever handle 50 is released, spring 54 forces lever handle awayfrom slots 16, thus moving latch 52 into an available slot 16. Sinceheight adjustment assemblies are typically installed near the ends ofchanging table 12, and when pushing lever handle 50 the user's hands arein contact with the underside of changing table 12, it is not at alldifficult to operate two lever handles simultaneously and also raise orlower changing table 12.

FIG. 3 is a side view of alternate embodiment 60 of the heightadjustment assembly of the invention. Support structure 20, tube 22, andcoupling ring 26 of height adjustment assembly 60 are identical to andserve the same function as the same parts of height adjustment fixture11 in FIGS. 1 and 2 so they are identified by the same numbers. Thedifference in height adjustment assembly 60 is in the recess and landstructure. Alternating slots 62 and lands 64 of height adjustmentassembly 60 are constructed to operate as rack 61 in conjunction withgear 66 so the spacing of lands 64 must match the spacing of teeth 68 ongear 66. The height adjustment is then accomplished by rotating gear 66in the appropriate direction.

Gear 66 is mounted upon and attached to the changing table (not shown inFIG. 3) in a manner similar to lever 46 of FIG. 1, so that as gear 66literally climbs up rack 61, the changing table is raised. Thiseliminates the requirement to manually lift the changing table to adjustthe height.

Gear 66 can be rotated by any conventional means. One rotating device isshown in FIG. 3. Knob 70 is mounted on surface 72 of the changing table(not shown) and drives gear 66 by conventional linking means 74 eitherdirectly or through a reduction drive. One requirement for any heightadjustment assembly is that it have some sort of latching device toprevent the changing table from moving down with increased weight. Thelatching device is provided for height adjustment assembly 60 at knob70. Knob 70 includes latch 76 that is pushed outward by spring. 78 andmoves into slots 80 to prevent both knob 70 and gear 66 from turningunless latch 76 is pulled into knob 70 by moving tab 79 against spring78. Latch 76 is only one of many conventional devices to permit lockingknob 70. Another such device is a tab on a spring loaded shaft thatmates with slots around the shaft unless moved axially to disengage thetab from the slots for turning the shaft.

FIG. 4 is a perspective view of another alternate embodiment of a heightadjustment assembly 84 of the invention with only partial structure 86of the changing table shown. Similar to the changing table 12 of FIG. 1,changing table structure 86 has changing table support 88 attached sothat support 88 can be installed into a holding fixture (not shown) onthe supporting structure upon which it will be supported. The essentialdifference between height adjustment assembly 84 and height adjustmentassembly 10 of FIG. 1 is that latches 90 are integrated with coupling 92into coupling and latch assembly 94. Coupling and latch assembly 94 thusminimizes the number of parts and simplifies the design of changingtable structure 86. All that is required within changing table structure86 are socket 96 (shown with invisible lines) within which coupling andlatch assembly 94 fits and holes 98 to mate with latches 90. As withheight adjustment assembly 10 of FIG. 1, height adjustment assembly 84permits changing table support 88 to slide within coupling 92 whenlatches 90 are depressed, and changing table structure 86 and the entirechanging table are raised as coupling and latch assembly 94 slideswithin socket 96. Releasing latches 90 then permits them to mate withother holes 98 and hold the changing table at a different height.

FIG. 5 is a perspective view of coupling and latch assembly 94 of heightadjustment assembly 84 of FIG. 4. Latches 90 are mounted upon spring 100so that simply pressing latches 90 in toward the center of supportstructure 102 flexes spring 100 and releases the latches from holes 98in changing table structure 86 (FIG. 4). This simple mechanism onsupport structure 102 eliminates the need for an external latchingmechanism on the changing table. It should be understood that therectangular configuration of support 102 and the use of pairs of latches90 and twin holes 98 (FIG. 4) are not vital to the function of heightadjustment assembly 84, and many other configurations of thesestructures can be used.

The invention thus provides a convenient and easily manufactured heightadjustment for a changing table used in conjunction with a play yard orany other supporting structure, and it requires no complex modificationof the supporting structure or the changing table supports because theheight adjustment assembly is external to those supports.

It is to be understood that the form of this invention as shown ismerely a preferred embodiment. Various changes may be made in thefunction and arrangement of parts; equivalent means may be substitutedfor those illustrated and described; and certain features may be usedindependently from others without departing from the spirit and scope ofthe invention as defined in the following claims. For example, springsother than leaf spring 54 as shown can be used, or height adjustmentfixture 11 can use holes or any other type of recesses within supportstructure 20 instead of slots 16, and the latch can be a spring loadedretractable pin instead of pivoting latch 52. Furthermore, neither thechanging table support nor the coupling of the height adjustmentassembly need to have cylindrical cross sections, nor the coupling evenbe a ring, as long as they mate, can be assembled together, and thesupport can move within the coupling.

1. A height adjustment assembly for a changing: table comprising: achanging table support (30) attached to a changing table and moveablevertically relative to a holding fixture (36) attached to a supportingstructure (14) upon which the changing table support (30) is supported;a coupling coupled to the changing table support (30) and permitting thechanging table support (30) to move relative to the coupling; a supportstructure (20) attached to the coupling and extending from the couplingand oriented toward the changing table and in the direction of movementof the changing table support (30) so that the changing table support(30) moves relative to the support structure (20); at least two recessesin the support structure (20), with the recesses aligned in thedirection of movement of the changing table support (30); and a latchingmechanism attached to the changing table and oriented to mate with therecesses on the support structure (20) as the changing table moves toplace each recess adjacent to the latching mechanism, with the latchingmechanism being releasable.
 2. The height adjustment assembly of claim 1wherein the coupling is a ring within which the changing table support(30) slides.
 3. The height adjustment assembly of claim 1 wherein therecesses are slots separated by lands.
 4. The height adjustment assemblyof claim 1 wherein the latching mechanism is a pivoting lever with arelease handle at one end and a latch at the other end with a springforcing the latch into the recesses in the support structure (20). 5.The height adjustment assembly of claim 1 wherein the recesses areequally spaced between a series of lands and the latching mechanism is agear with teeth that mate with the recesses.
 6. The height adjustmentassembly of claim 1 wherein the recesses are equally spaced between aseries of lands, the latching mechanism is a gear with teeth that matewith the recesses, the gear is interconnected with a knob by which thegear is rotated, and the knob is interconnected with a releasable latchthat prevents the gear from turning.
 7. The height adjustment assemblyof claim 1 wherein the support structure (20) includes a spring actingto separate the changing table from the support structure (20) in thedirection of movement of the changing table support (30).
 8. A heightadjustment assembly for a changing table comprising: a changing tablesupport (88) attached to a changing table (86) and moveable verticallyrelative to a holding fixture (36) attached to a supporting structure(14) upon which the changing table support (88) is supported, with thechanging table (86) including a socket (96) within the body of thechanging table (86); a coupling (92) coupled to the changing tablesupport (88) and permitting the changing table support (88) to movevertically relative to the coupling (92); a latch assembly (94) attachedto the coupling (92) and extending from the coupling (92), inserted intosocket (96) within the body of the changing table (86), and oriented inthe vertical direction of movement of the changing table support (88);at least two recesses (98) in the body of the changing table (86), withthe recesses (98) aligned in the vertical direction of movement of thechanging table support (88) and to fit into the socket (96) within thebody of the changing table (86) and; a latch (90) built into the latchassembly (94) and oriented to mate with the recesses (98) in thechanging table (86) as the changing table moves vertically to place eachrecess adjacent to the latch, with the latch (90) being located so thatthe latch (90) is releasable by a user while the user is simultaneouslyholding and vertically moving the changing table (86).
 9. The heightadjustment assembly of claim 8 wherein the latch (90) is attached to aspring integrated into the latch assembly (94).